# requests_vendor.py -- requests implementation of the AbstractHttpGitClient interface
# Copyright (C) 2022 Eden Shalit <epopcop@gmail.com>
#
# Dulwich is dual-licensed under the Apache License, Version 2.0 and the GNU
# General Public License as public by the Free Software Foundation; version 2.0
# or (at your option) any later version. You can redistribute it and/or
# modify it under the terms of either of these two licenses.
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# You should have received a copy of the licenses; if not, see
# <http://www.gnu.org/licenses/> for a copy of the GNU General Public License
# and <http://www.apache.org/licenses/LICENSE-2.0> for a copy of the Apache
# License, Version 2.0.


"""Requests HTTP client support for Dulwich.

To use this implementation as the HTTP implementation in Dulwich, override
the dulwich.client.HttpGitClient attribute:

  >>> from dulwich import client as _mod_client
  >>> from dulwich.contrib.requests_vendor import RequestsHttpGitClient
  >>> _mod_client.HttpGitClient = RequestsHttpGitClient

This implementation is experimental and does not have any tests.
"""
from io import BytesIO

from requests import Session

from dulwich.client import AbstractHttpGitClient, HTTPUnauthorized, HTTPProxyUnauthorized, default_user_agent_string
from dulwich.errors import NotGitRepository, GitProtocolError


class RequestsHttpGitClient(AbstractHttpGitClient):
    def __init__(
            self,
            base_url,
            dumb=None,
            config=None,
            username=None,
            password=None,
            **kwargs
    ):
        self._username = username
        self._password = password

        self.session = get_session(config)

        if username is not None:
            self.session.auth = (username, password)

        super(RequestsHttpGitClient, self).__init__(
            base_url=base_url, dumb=dumb, **kwargs)

    def _http_request(self, url, headers=None, data=None, allow_compression=False):
        req_headers = self.session.headers.copy()
        if headers is not None:
            req_headers.update(headers)

        if allow_compression:
            req_headers["Accept-Encoding"] = "gzip"
        else:
            req_headers["Accept-Encoding"] = "identity"

        if data:
            resp = self.session.post(url, headers=req_headers, data=data)
        else:
            resp = self.session.get(url, headers=req_headers)

        if resp.status_code == 404:
            raise NotGitRepository()
        if resp.status_code == 401:
            raise HTTPUnauthorized(resp.headers.get("WWW-Authenticate"), url)
        if resp.status_code == 407:
            raise HTTPProxyUnauthorized(resp.headers.get("Proxy-Authenticate"), url)
        if resp.status_code != 200:
            raise GitProtocolError(
                "unexpected http resp %d for %s" % (resp.status_code, url)
            )

        # Add required fields as stated in AbstractHttpGitClient._http_request
        resp.content_type = resp.headers.get("Content-Type")
        resp.redirect_location = ""
        if resp.history:
            resp.redirect_location = resp.url

        read = BytesIO(resp.content).read

        return resp, read


def get_session(config):
    session = Session()
    session.headers.update({"Pragma": "no-cache"})

    proxy_server = user_agent = ca_certs = ssl_verify = None

    if config is not None:
        try:
            proxy_server = config.get(b"http", b"proxy")
            if isinstance(proxy_server, bytes):
                proxy_server = proxy_server.decode()
        except KeyError:
            pass

        try:
            user_agent = config.get(b"http", b"useragent")
            if isinstance(user_agent, bytes):
                user_agent = user_agent.decode()
        except KeyError:
            pass

        try:
            ssl_verify = config.get_boolean(b"http", b"sslVerify")
        except KeyError:
            ssl_verify = True

        try:
            ca_certs = config.get(b"http", b"sslCAInfo")
            if isinstance(ca_certs, bytes):
                ca_certs = ca_certs.decode()
        except KeyError:
            ca_certs = None

    if user_agent is None:
        user_agent = default_user_agent_string()
    session.headers.update({"User-agent": user_agent})

    if ca_certs:
        session.verify = ca_certs
    elif ssl_verify is False:
        session.verify = ssl_verify

    if proxy_server:
        session.proxies.update({
            "http": proxy_server,
            "https": proxy_server
        })
    return session
